Help: 2002 AWD Rolls in Park

I have 2002 AWD V8 Mountaineer Auto Tranny. I removed the front drive shaft because the joint is bad. Now the truck will roll in park if the parking brake is not on hard. I know the transfer case has a viscous coupling that can slip and I read on another bulletin board that roll is normal with the front drive shaft removed. However, I thought that the rear output of the transfer case is directly connected to the input from the transmission, with the viscous coupling only driving the front output shaft. Am I right and if so, does that mean that the parking prawl in the automatic trans is not working correctly? If there is a problem with the parking prawl, can it be repaired/adjusted without a trany overhaul? Apprecate any help as this has become a safety issue as my wife tends not to press hard enough on the parking brake and today it started to roll after she parked. I adjusted the parking brake to work better and I'm in the process of getting a new front shaft, but if I need to fix the parking prawl as well I need to know. Thanks.